Processing methods using adaptive threshold for removal of chroma/luminance cross-talk in quadrature-modulated subcarrier color television systems

A method for controlling the operation of a luminance comb filter in a color television system including the steps of:

• chrominance-type comb filter processing of at least that portion of a luminance component of a quadrature modulated color subcarrier television signal filter interleaved in the spectrum of the color subcarrier pass band and band pass filtering the luminance component to limit it to the spectrum of said color subcarrier pass band to provide a band pass filtered and combed luminance component, subjecting the band pass filtered and combed luminance component to a variable threshold below which said band pass filtered and combed luminance component is inhibited and above which said band pass filtered and combed luminance component is passed, subtracting said band pass filtered and combed luminance component as passed by said variable threshold from a delay matched original luminance component to provide a combed original luminance component whenever said band pass filtered and combed luminance component is passed and a non-combed original luminance component whenever said band pass filtered and combed luminance component is not passed.